Basic RAID question

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Archived from groups: comp.sys.ibm.pc.hardware.storage (More info?)

When setting two SATA IDE drives in RAID for fastest performance (RAID 0 ?)
with two mirroring drives, is the total capacity a sum of each drives
capacity, or equal to only half the total?

Pardon my ignorance, as I am a SCSI guy.

Jorge

 

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Archived from groups: comp.sys.ibm.pc.hardware.storage (More info?)

"Jorge E. Ravelo" wrote:
>
> When setting two SATA IDE drives in RAID for fastest performance (RAID 0 ?)
> with two mirroring drives, is the total capacity a sum of each drives
> capacity, or equal to only half the total?
>
> Pardon my ignorance, as I am a SCSI guy.
>
> Jorge

Raid 0 and mirroring are an oxymoron.

Raid 0 (striping) will give you twice the capacity of the smaller drive.

Raid 1 (mirroring) will give you the capacity of the smaller drive.

Obviously it is standard practice to use identical drives across the
array.

A "SCSI guy" should be more in the nous than anyone else!

Odie
--

RetroData
Data Recovery Experts
www.retrodata.co.uk

 

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Archived from groups: comp.sys.ibm.pc.hardware.storage (More info?)

"Odie Ferrous" <odie_ferrous@hotmail.com> wrote in message
news:4128BD03.E564F409@hotmail.com...


> A "SCSI guy" should be more in the nous than anyone else!
>
> Odie
> --
>
> RetroData
> Data Recovery Experts
> www.retrodata.co.uk


Thanks for your response OF!

The reason I am such an ignoramus is that with my Adaptec 2940UW
controller I am not able to mirro/strip anything as it is a non-RAID
controller.
This card, with my original Quantum Atlas 10K drive has served me faithfully
and transparently through many a PC rebuild, possibly four different setups
since purchased! Now it resides in a Pentium 4 ASUS p4800E-Deluxe mobo that
has a SATA Promise RAID controller, and as my supplementary IDE HD (a WD
78mb buffer 80 Gb)( is slower than the Atlas, I thought setting up a RAID
stripping setup with two WD 10 k RAPTORS would speed up the system.

Have a good evening,

Jorge

 

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Archived from groups: comp.sys.ibm.pc.hardware.storage (More info?)

Most modern OS will stripe or mirror your SCSI drives on that 2940UW with no
problem. It isn't quite as fast as a dedicated RAID card, but it can be
done.

--Dan

"Jorge E. Ravelo" <jorge@ravelo.org> wrote in message
news:McKdnX18PutVXLXcRVn-ug@comcast.com...
> Thanks for your response OF!
>
> The reason I am such an ignoramus is that with my Adaptec 2940UW
> controller I am not able to mirro/strip anything as it is a non-RAID
> controller.
> This card, with my original Quantum Atlas 10K drive has served me
faithfully
> and transparently through many a PC rebuild, possibly four different
setups
> since purchased! Now it resides in a Pentium 4 ASUS p4800E-Deluxe mobo
that
> has a SATA Promise RAID controller, and as my supplementary IDE HD (a WD
> 78mb buffer 80 Gb)( is slower than the Atlas, I thought setting up a RAID
> stripping setup with two WD 10 k RAPTORS would speed up the system.
>
> Have a good evening,
>
> Jorge
>
>
>
>
>

 

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Archived from groups: comp.sys.ibm.pc.hardware.storage (More info?)

"Jorge E. Ravelo" <jorge@ravelo.org> wrote in message news:McKdnX18PutVXLXcRVn-ug@comcast.com...
> "Odie Ferrous" <odie_ferrous@hotmail.com> wrote in message news:4128BD03.E564F409@hotmail.com...
>
> > A "SCSI guy" should be more in the nous than anyone else!
> >
> > Odie
>
> Thanks for your response OF!
>
> The reason I am such an ignoramus is that with my Adaptec 2940UW
> controller I am not able to mirror/stripe anything as it is a non-RAID controller.
> This card, with my original Quantum Atlas 10K drive has served me faithfully
> and transparently through many a PC rebuild, possibly four different setups
> since purchased! Now it resides in a Pentium 4 ASUS p4800E-Deluxe mobo that
> has a SATA Promise RAID controller,
> and as my supplementary IDE HD (a WD 8MB buffer 80 GB)

> is slower than the Atlas,

And an original Atlas 10K is already quite slow itself, compared to that 80GB WD.

> I thought setting up a RAID stripping setup with two WD 10k RAPTORS
> would speed up the system.

If your slow Atlas beats an 80GB WD then you must be doing lots and lots
of small record IO, almost entirely. Even one Raptor should beat the Atlas.

What you need is better access time, not better STR.

>
> Have a good evening,
>
> Jorge
>

 

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Archived from groups: comp.sys.ibm.pc.hardware.storage (More info?)

dg wrote:
>
> Most modern OS will stripe or mirror your SCSI drives on that 2940UW with no
> problem. It isn't quite as fast as a dedicated RAID card, but it can be
> done.
>

I believe (this is certainly the case with Microsoft products; not sure
about Linux, etc.) you can only stripe a second partition; one cannot in
any way have the OS itself run on a RAID array.

I have not done it myself, but I have also heard the results are quite
efficient, speed-wise.

Odie
--

RetroData
Data Recovery Experts
www.retrodata.co.uk